Process op manufacturing bits



June 19, 1928. 1,674,318

R. P. CARR PROCESS OF MANUFACTURING BITS Filed Dec. 28, l 2 Sheets-Sheet l WWI/17am June 19, 1928. 1,674,318

R. P. cARR PROCESS OF MANUFACTURING BITS Filed Dec. 28, 1925 2 Sheets-Sheet 2 9 L M 25 a? r 37/2 ATTORNEY? Patented June 19, 1928.

ROBERT P. CARR, OF BUFFALO,

PROCESS OF MANUFACTURING BITS.

Application filed December 28, 1923.

at the middle part of the mouth piece, and v 10 known as a jointed ring bit. The mouth piece is provided with enlarged outer ends in which the usual rein rings are swivelled. In the manufactureof bits of this type,

as at present. practised, the mouth pieces have been formed either as a malleable casting having the apertures for the rein rings formed at the time of casting,'or drilled after casting,or by using a steel rod section, in one or two parts as the case may be, and either forging the enlarged ends so as to provide the apertures for the rein rings or bending each of the ends of the bit around on itself to form the rein ring apertures. In the first mentioned case the malleable casting provides an inferior and relatively rough article not having the straight and smooth appearance requisite for a first class bit, while the forged bit is relatively expensive to manufacture and, unless great care is taken in forming the enlarged ends with the apertures therein, the joining of the metal will be rough and an imperfect bit will result.

The objects of the'present invention are toimprove the manufacture of mouth pieces for bits to overcome the objections stated, and to provide a mouth piece which can be more economically manufactured than mouth pieces made by the processes heretofore in use. i

In the accompanying drawings:

Fig.1 illustrates the first step in the practical application of the process of manufacture of bitsin accordance with the invention, showing in sectional elevation a set of gripping and upsetting dies, in aninoperative position, with a wire blank or rod adjacent thereto before being inserted into the dies.

55 Fig. 4 is a similar view showing the oper- Fig. 2 is a sectional plan view thereof,

Serial No. 683,209.

ation of the dies for the final upsetting operation.

Fig. 5 is an end view of the gripping dies in open position.

Fig. 6 is a view of the blank after the enlarged end has been formed thereon by the dies illustrated in Figs. 15.

Fig. 7 is a fragmentary face view of one of a pair of dies used for forming an eye on the other end of the blank or rod.

Fig. 8 is a fragmentary sectional elevation of the pair of dies, shown in Fig. 7 with the blank of Fig. (5 in operative relation thereto.

Fig. 9 is a face view of the blank after the enlarged end and an eye have been formed at its opposite ends. 1

Fig. 10 is a similar view, showing two of the members illustrated inFig. 9, to disclose the method of connecting them to form the mouth piece of the bit.

Fig. 11 is a similar view thereof, after the apertures have been provided in the enlarged ends for the reception of the rein rings. I

Fig. 12 is an enlarged fragmentary section of one of the enlarged ends of the mouth piece.-

Fig. 13 is a view similar to Fig. 11, partly in section, but with the rein rings in the apertures in the enlarged ends.

Fig. 14: is a sectional elevation showing the bit, as illustrated in Fig. .13, in operative relation to a pair of bending dies.

Fig. 15 is a view of a bit after being operated upon in the bending dies.

Fig. 16 is a view of a mouth piece formed of a single member,

According to the present embodiment of the invention as disclosed in the drawings, the bit is made in a simple and quick manner by die operations and drop forgin Theenlarged endsare substantially spherical in form with connecting neck portions of uniform curvature or taper merging gradually into the bar portions of the mouth piece without breaks or irregularities and with a surface that can be tinned or nickel plated without any preliminary smoothing or finishing operations other than the usual tumbling.

In practice the mouth pieces are formed from suitable material such as steel wire of desired size, which is cut to the required length to form the wire blank 10, Figs. 1

and 2, as by a cutting mechanism (not shown) which may be a part of the die press machine, which machine is also adapted to feed the cut blanks to a pair of combined gripping and end forming dies BB. Each of these dies is provided with complementary half round grooves 11 terminating-in enlargements 12. The enlargements 12 are curved and together form a substantially hemispherical recess 13 at the outer end of the dies. The dies BB, are normally spaced apart as shown in Fig. 1 but are adapted to move towards each other when a blank has been fed between them so as to grip the blank, with its outer or front end extending beyond the recess 13 as in Fig. 2. When a blank 10 has been gripped by the forming and gripping dies, these dies are moved laterally so as to bring the blank into axial alinement with an upsetting die C, which, together with a final forming die C are mounted in a reciprocating head C In the lateral movement of the dies BB they preferably move in front of a stationary block D, against which the rear end of the blank 10 may abut, thereby providing a resistance to endwise movement of the blank in the dies BB during the formation of the enlarged end. The upsetting of the end of the blank is carried out first by the movement of the upsetting die (1 toward the projecting end of the blank 10, which die is adapted to engage and deform the end as shown at 14, Fig. 3. The head. C now moves first away from the gripping dies BB to disengage the upsetting die C and then moves upwardly and towards the dies BB to present the final forming die C to the upset end 14 of the blank. The final die C for forming the enlarged end of the blank is provided with a hemispherical seat or recess 15, of the same size as the recess 13 in the holding dies. The die C is adapted to engage the upset end 14 of the blank and force it into the substantially spherical form shown at 16 in Figs. 4 and 6 by pressing the metal into the complementary recesses 13 and 15.

The foregoing description particularly relates to the formation of the bar portions 20 for the mouth pieces used in the manufacture of jointed ring hits as shown in Figs, 10 to 15, but it should be understood that the well known type of stiff or single mouth pieces, such as shown at 20 in Fig. 16 may as readily be provided with the enlarged ends 16 formed in the manner described.

The forming of the enlarged ends of the mouth piece of the bit is done without a preliminary heating of the blanks, which are fed to the dies and formed into shape while cold. This part of the process effects a great saving in the cost of production of the bits, and also, makes it possible to produce a mouthpiece which is comparatively free fromimperfections, so that no polishing or grinding is necessar on the mouthpieces prior to tinning, nicke plating or other finishing operations.

In the production of the jointed mouth piece bits, it is necessary to provide the separate bar portions 10 with eyes or link portions 21 whereby the bar portions may be linked together to form the loose joint 21 of the bit, and this may be done in the same manner heretofore employed in the manufacture of drop forged mouth pieces. For this purpose the bar portion is first heated and then subjected to the action of a set of primary and secondary eye forming dies EE, see Figs. '4' and 8. These dies comprise upper and lower complementary portions, and one half of each die may be conveniently formed integrally in a single block as in Fig. 7. Each die is provided with channel portions for the reception of the bar portion 10 and the primary die E is formed with substantially annular cavities 23, one of which is shown in Fig. 7 for partially forming the eye 21, the eye being completed by the annular cavities 24 of the secondary die E. The bar portion 10" may be presented to the dies EE in any suitable manner as by the gripping member F, Fig. 8, which is adapted to grip the enlarged end 16, and maintain the opposite end of the bar 10 in proper relation to the eye forming cavities so that these parts of the die may compress the end of the bar into the desired formation. The eyes may then be connected in any usual or suitable manner, the preferred method of connecting the eyes 21 to form the joint 21 being to cut through the metal as at 22, open or spread the cut, and insert the other eye, after which the severed metal may be rejoined by bending the parts back to their original positions. The heating of the blank after one end thereof has been upset while cold also has the advantage of re.- lieving any strains that may have been created in the upset end during the cold upsetting operation or of eliminating any crystallization that may have taken place.

The next step in the production of either the jointed bit or the single bar bit 20 is to drill a hole 25 in each enlarged end, and then to countersink the metal at opposite ends of the hole as shown at 25 Fig. 12. It should be understood that these ring receiving apertures may be formed by any other suitable means.

After the mouth pieces have been formed as described, they may be subjected to a tumbling operation, if necessary, to, remove any slight roughness orseams such as are sometimes produced in the use of (lies. The rein rings 27 are now insertedinthe apertures 25. These rings are of usual form adapted to swivel or have easy move-. ments relative to the mouth piece.

It is usual to curve or bend the mouth pieces of bits of this kind, as shown in Figs. 15, 16, and for this purpose suitable dies GG' are used, see Fig. 14. The bit is placed, while cold, in proper position on the die G which is stationary, and the upper die Gis adapted to reciprocate and engage the mouth piece of the bit and bend or curve it to the desired degree. The bit is now complete'and is ready for the usual tinning, nickel plating, or other finishing operation.

By means of the process described, bits can be made more economically than was heretofore possible and the bits so produced are of high quality and are free from projections or rough places, so that in addition to the saving effected by forming the metal, While cold, toproduce the enlarged ends thereof, the grinding or smoothing generally necessary on bits made by other processes may be dispensed with.

I claim as my invention:

1. In the hereindescribed process of manufacturing mouthpieces for bits, the steps of presenting an end of a cylindrical wire blank to the action of successive sets of upsetting dies and shaping the end of said blank, while cold, into an enlarged rounded end by means of a plurality of upsetting operations, providing an aperture in said enlarged end for the reception of a rein ring, and heating and then cooling the blank at the rounded end subsequent to the formation of the rounded end to permit molecular readjustment of the metal at the rounded end.

2. In the hereindescribed process of manufacturing mouthpieces for hits, the steps of presenting an end of a cylindrical wire blank, while cold, to the action of a pair of upsetting dies, the first of said dies artially upsetting an end of said blank," and the second of said dies forming an enlarged rounded end on said blank, heating the blank after the forming of said enlarged end, providing an aperture in said enlarged end for the reception of a rein ring. and forming an eye in the other end.

3. The hereindescribed process of manufacturing mouthpieces for bits, which consists of presenting a cylindrical wire blank, while cold, to the action of upsetting dies and forming an enlarged rounded end on one end of said blank, heating said blank to relieve strains in said rounded end, form-- ing an eye on the other end of said blank while the same is heated, connecting the eyes of two of said blanks, forming apertures in said enlarged ends for the recep tion of rein rings, and bending said mouth pieces while cold to give the same the desired curvature.

4. In the manufacture of mouthpieces for bits, the steps which comprise upsetting, while cold, an end of a wire blank into an enlarged rounded head, forming a hole in said head, upsetting the other end of the blank to form an uncut terminal eye, and heating and then cooling the blank subsequent to the formation of said head to permit molecular readjustment of the upset parts of the blank.

5. In the manufacture of mouthpieces for bits, the steps which comprise upsetting,

while cold, an end of a wire blank into an enlarged rounded head, forming a hole in said head, upsetting the other end of the blank to form an uncut terminal eye, forming a second blank in the same manner, cutting and spreading the terminal eye of one blank, passing it through the other eye, and then bending the cut eye back into shape to close it.

ROBERT P. CARR. 

